Process for making 1-pyrrolidinyl methyl ferrocene

ABSTRACT

The product 1-pyrrolidinyl-methylferrocene, the process of making the compound 1-pyrrolidinyl-methylferrocene, and the use of the compound 1-pyrrolidinyl-methylferrocene in composite propellant compositions. 1-pyrrolidinyl-methylferrocene is made by reacting dimethylaminomethylferrocene methyliodide or (ferrocenylmethyl)trimethylammonium iodide in the presence of aqueous sodium hydroxide solution and pyrrolidine. This mixture is reacted by mechanically stirring and maintaining the reflux temperature for approximately 6 hours, the product is then recovered.

United States Patent [191 Van Landuyt et al.

[ PROCESS FOR MAKING l -PYRROLIDINYL METHYL FERROCENE [75] Inventors:Dennis C. Van Landuyt, Auburn;

Orval E. Ayers, Huntsville, both of Ala.

[73] Assignee: The United States of America as represented by theSecretary of the Army, Washington, DC.

[22] Filed: June 15, I971 [2]] Appl. No.: 155,672

[52] U.S. Cl. 260/326.8; 260/439 CY [5 l] lnt. Cl. C07!) 207/04; C07F15/02 [58] Field of Search 260/3 26.8. 439 CY [56] References CitedUNITED STATES PATENTS l/l958 Tesoro et al 260/3268 OTHER PUBLICATIONSBieber et al., J. Org. Chem.. 29 (7). 2028-203O Perevalova et al., Izv.Akad. Nauk SSSR, Otd. Khim Nauk, 1036-l045 (I963).

[ Dec. 9, 1975 Nesmeyanov et al., ibid. l997-200l. (1962).

Morrison et al.. Organic Chemistry. pp. 531-532. 553454, Allyn & Bacon,lnc.. (1965) Boston.

Primary ExaminerBenjamin R. Padgett Assistant Examiner-E. A. MillerAttorney, Agent. or Firm-Nathan Edelberg; Robert P. Gibson; James T.Deaton [57] ABSTRACT 1 Claim, N0 Drawings PROCESS FOR MAKINGl-PYRROLIDINYL METHYL FERROCENE BACKGROUND OF THE INVENTION Ferrocenesare usually used in the liquid form as ballistic modifiers in solidpropellant compositions and they also serve as plasticizing agents. Inthe liquid stage, some ferrocene additives exhibit inherentdisadvantages that are characteristic of liquid additives such as lossby evaporation, migration, etc., and consequently, propellant systemsoften suffer when stored for long periods of time. Therefore, there is agreat need for perfecting ferrocene compounds for use in solidpropellant compositions as ballistic modifiers, bonding agents, andprocessing aids to improve the mechanical properties of propellantcompositions.

Accordingly, it is an object of this invention to provide the compoundl-pyrrolidinyl-methylferrocene.

Another object of this invention is to provide a novel process formaking l-pyrrolidinyl-methylferrocene.

A further object of this invention is to provide a coating agent forammonium perchlorate, which coating also acts as a bonding agent.

Still another object of this invention is to provide the compoundl-pyrrolidinyl-methylferrocene as a processing aid, bonding agent, andballistic modifier in composite propellant compositions to improve themechanical properties thereof.

A still further object of this invention is to provide the compoundl-pyrrolidinyl-methylferrocene for use in solid propellant compositionsto vary the burning rates of various solid propellants.

SUMMARY OF THE INVENTION In accordance with this invention, the novelcompound l-pyrrolidinyl-methylferrocene is produced by reacting(ferrocenylmethyl)trimethylammonium iodide ordimethylaminomethylferrocene methyliodide, aqueous sodium hydroxidesolution and pyrrolidine in a mechanically stirred mixture and at areflux temperature for about 6 hours. The reaction product yields 1-pyrrolidinyl-methylferrocene. This product can then be used as a bondingagent to coat the surface of the oxidizer. Coating of an oxidizer suchas ammonium perchlorate is accomplished by dissolving the product inmethylene chloride and then adding this solution to a quantity ofammonium perchlorate. The mixed solution is allowed to stand overnightto insure complete coating of the ammonium perchlorate. The ammoniumperchlorate coated with the compound l-pyrrolidinylmethylferrocene isincorporated in propellant compositions that contain other ingredientssuch as a binder, curing agents, metal fuel, and processing aids asdesired. Propellant compositions using the compound 1-pyrrolidinyl-methylferrocene in quantities of to 10 weight percent canhave the burning rates thereof increased to more than'200 percent incomparison to propellant compositions without the novel compound.

DETAILED DESCRIPTION OF THE INVENTION Synthesis ofl-pyrrolidinyl-methylferrocene. In a 500 ml round-bottom flask equippedwith mechanical stirrer and reflux condenser, the following reactantswere placed: 150 g(0.39 mole) dimethylaminomethylferrocene methyliodideor (ferrocenylmethyl)trimethylammonium iodide, I20 ml of 1 molar aqueoussodium hydroxide solution, 100 ml (1.20 moles) of pyrrolidine.

This mixture was mechanically stirred and maintained at refluxtemperature for 6 hours, and then the reaction product was extractedwith a 50-50 volume solution of benzene and heptane (450 ml required).The organic solution was dried over anhydrous MgSO and evaporated. Yield76.3 grams (0.29 moles) of l-pyrrolidinyl-methylferrocene. The structureof this compound was confirmed by N.M.R. and LR. spectra. Melting pointof this solid was found to be 50-50.5C.

As a bonding agent, the compound, l-pyrrolidinylmethylferrocene, iscoated on the surface of an oxidizer, preferably ammonium perchlorateusing 0.2 percent or more coating. Coating of the oxidizer surface isaccomplished by dissolving the l-pyrrolidinyl-methylferrocene inmethylene chloride and then adding this solution to a quantity ofoxidizer. After thoroughly mixing, the solution is allowed to standovernight to insure complete coating of the oxidizer. The amount ofcompound necessary to coat the oxidizer will depend upon the totaloxidizer surface area. Propellants are processed using thisl-pyrrolidinyl-methylferrocene coated oxidizer. The bonding agent forthe oxidizer acts as a processing aid, bonding agent, and ballisticmodifier for the propellant composition, and improves the mechanicalproperties of composite propellants.

Basically, propellant compositions according to this invention comprisea binder of about ID to about 25 weight percent, a metal fuel of about 5to about 20 weight percent, an oxidizer of about 50 to about weightpercent, and l-pyrrolidinyl-methylferrocene of an amount of about 0.1 toabout 20 weight percent and preferably from about 0.2 to about l0 weightpercent. Also, depending upon the particular propellant composition,small amounts of conventional curing agents and conventional processingaids may be used as necessary to accomplish the desired mixing andcuring of the propellant compositions.

Binders according to this invention may be selected from carboxyterminated polybutadiene, hydroxy terminated polybutadiene,polybutadiene acrylic acid, and other hydro carbon binders.

Metal fuels useful in this invention include metal powders as additivesin the propellant compositions according to the invention. These metaladditives include in addition to the preferred metal powder aluminum,magnesium, titantium, zirconium, and boron. Alloys and mixtures of theaforesaid metals may also be employed.

Inorganic oxidizing salts which are useful in the solid propellantcompositions of this invention are those oxygen containing salts whichreadily give up oxygen. Even though other oxidizing salts may be usedwith the propellant compositions of this invention, ammonium perchlorateis preferred with the propellant compositions sincel-pyrrolidinyl-methylferrocene acts as a binder coating for ammoniumperchlorate. Further, ammonium perchlorate is preferred since less smokeresults from lower solids present in exhaust gases from a rocket motorwherein ammonium perchlorate is used. Lower smoke solids are requiredfor military purposes of concealment. Further, ammonium perchlorate ispreferred since is available in large as well as small particle sizes.

Examples of composite propellant compositions according to thisinvention:

-continued EXAMPLE I by Weight Ammonium erchlorate (l7 micron) 49.00 byWeight l-pyrrolidiny -methylferrocene Carboxy terminated polybutadienel7.8l Tris [l-( Z-methyl)aziridinyl1phosphine oxide .56 ERLA' 0510 .l8We claim:

Aluminum (H-IO) 10.00 Pym,fidinyhmehylfemcene 5.00 l. The process ofproducing [pyrrolrdmyl methyl Ammonium Perchlorate (I 5 micron) 6645ferrocene comprising reacting a mixture of (ferrocenyl- Lecithin (added)0 m methyl) trimethylammonium iodide, aqueous sodium Trim 0 a] M db shCh 1C hydroxide solution and pyrrolidine in a container that W m y mpmmhas a mechanical stirrer and reflux condenser, mechanically stirring themixture and maintaining the mixture This propellant composition gave aburning rate of at reflux temperature for about 6 hours to produce a0.99 inlsec at 2000 psia. A control composition similar macho" P'f Pextractmg the macho" to the above containing no catalyst gave a burningrate product 3 sultabl? i i' of 05 insea methyl) trimethylammonlumiodide being present in a proportion of about I50 grams to about 120 mlof 1 EXAMPLE [1 molar solution of said aqueous sodium hydroxide, and

to about 100 ml of said pyrrolidine, and said solvent sob w m lutionbeing about a 50-50 volume solution of beny zene and heptane, saidreaction product being dried Carboxy terminated polybutadiene I I l6.l30V6! BI'IhydIOLIS MgSO and evaporated (0 yield the 21kggfg product saidl-pyrrolidinylmethylferrocene with a Aluminum [3:00 melting point fromabout 50 to 505C. Ammonium perchlorate (200 micron) 2l.00

1. THE PROCESS OF PRODUCING 1-PYRROLIDINYL-METHYLFERROCENCE COMPRISINGREACTING A MIXTURE OF (FERROCENYLMETHYL) TRIMETHYLAMMONIUM IODIDE,AQUEOUS SODIUM HYDROXIDE SOLUTION AND PYRROLIDINE IN A CONTAINER THATHAS A MECHANICAL STIRRER AND REFLUX CONDENSER, MECHANICALLY STIRRING THEMIXTURE AND MAINTAINING THE MIXTURE AT REFLUX TEMPERATURE FOR ABOUT 6HOURS TO PRODUCE A REACTION PRODUCT, AND THEN EXTRACTING THE REACTIONPRODUCCT WITH A SUITABLE SOLVENT, SAID (FERROCENYLMETHYL)TRIMETHYLAMMONIUM IODIDE BEING PERSENT IN A PROPORTION OF ABOUT 150GRAMS TO ABOUT 120 ML OF 1 MOLAR SOLUTION OF SAID AQUEOUS SODIUMHYDROXIDE, AND TO ABOUT 100 ML OF SAID PYRROLIDINE, AND SAID SOLVENTSOLUTION BEING ABOUT A 50-50 VOLUME SOLUTION OF BEBZENE AND HEPTANE,SAID REACTION PRODUCT BEING DRIED OVER ANHYDROUS MGSO4 AND EVAPORATED TOYIELD THE PRODUCT SAID 1-PYRROLIDINYLMETHYLFERROCENE WITH A MELTINGPOINT FROM ABOUT 50* TO 50.5*C.